VHF400MHz Wireless-Access Fiber Optical Tetra Repeater Mobile Signal Repeater

Wireless-Access Fiber Optical Repeater Description:

Today's users of mobile devices depend on wireless connections for their voice, data and even video communications. Even homes and businesses may depend on wireless, especially those who are not in urban or suburban areas served by FTTH (fiber to the home) or FTTC (fiber to the curb.) Some of us in the business now use the term FTTW for fiber to wireless, since wireless depends on fiber for the communications backbone and increasingly the connection to the wireless antennas, no matter what kinds of wireless we use.

Greetwin Fiber Optic Repeaters system is designed to solve problems of weak mobile signal, which is much cheaper than setup a new Base Station (BTS). Main operation of RF Repeaters system: For the down link, signals from BTS is fed to Master Unit(MU), the MU then convert RF signal to laser signal then feed to fiber to transmit to Remote Unit(RU). RU then convert laser signal to RF signal, and use Power Amplifier to amplify to high power to IBS or coverage antenna. For the up link, Is a reverse process, signals from user mobile is fed to MU’s MS port. Via duplexer, the signal is amplified by low noise amplifier to improve signal strength. Then the signals is fed to RF fiber optical module then converted to laser signals, then the laser signal is transmit to MU, the laser signal from RU is convert to RF signal by RF optical transceiver. Then the RF signals are amplified to more strength signals fed to BTS.

The Fiber Optic Repeater (FOR) is designed to solve problems of weak mobile signal in such place: Far away from the BTS (Base Transceiver Station) and has fiber optic cable network underground.
The whole FOR system consists of two parts: Donor Unit and Remote Unit. They transparently convey and amplify the wireless signal between the BTS (Base Transceiver Station) and mobiles via fiber optic cables.

The Donor unit captures the BTS signal via a direct coupler closed to the BTS (or via open air RF transmission through the Donor Antenna), then converts it into optic signal and transmits the amplified signal to the Remote Unit via fiber optic cables. The Remote Unit will reconvert the optic signal into RF signal and provide the signal to the areas where network coverage is inadequate. And the mobile signal is also amplified and retransmitted to the BTS via the opposite direction.

As per the method of receiving BTS signal by the Donor Unit, two types of FOR are available:
Cable-Access FOR: To receive BTS signal via a direct coupler closed to the BTS (recommended);
Wireless-Access FOR: To receive BTS signal via a Donor Antenna (applicable when no fiber optic cable connecting to the BTS); Can be sorted into 2 sub-categories: Band-Selective and Channel-Selective.

Wireless-Access Fiber Optical Repeater Features:

1. High level, high availability, convenient for maintain;

2. Internal adopt intelligent monitoring, is convenient to locate the faults for maintain;

3. Low power consumption, excellent heat dissipation;

4. High linearity PA, high system gain;

5. Local and remote monitoring (optional) with automatic fault alarm &remote control;

6. Compact size, flexible for installation and relocation;

7. Weatherproof design for all-weather installation;

8. One MOU can support Max 8 ROUs, Save cost and ease installation.

The FOR is mainly applicable to such case:
· Underground fiber optic cable network already exists beneath the area to be covered;
· There is huge obstructive terrain between the BTS and the area to be covered;
· The distance between the BTS and the area to be covered is 20 km around.

In comparison with RFR (RF repeater) and FSR (frequency shift repeater), the FOR has the following benefits and disadvantages:

Pro:
No more self-oscillation and easy to choose installation location;
For Cable-Access type, pure BTS signal picked up by the Donor Unit will greatly reduce the signal noise;
The Remote Unit can be installed out of the BTS coverage;
A full 360-degree coverage can be realized;
No need to occupy frequency resource as the link frequency.

Con:
· The total cost of equipment is higher;
· A fiber optical connection between the Donor Unit and Remote Unit is required.

Wireless-Access Fiber Optical Repeater Application:
To expand signal coverage or fill signal blind area where signal is weak or unavailable.
· Outdoor: Airports, tourism regions, golf courses, tunnels, factories, mining districts, villages, highways
· Indoor: Hotels, exhibition centers, basements, shopping malls, offices, parking lots.

Data Sheet:

Master Unit(MU) Technical Specification:

Remote Unit Technical Specification:

MOU+ROU Whole System Technical Specification:

Installation Location Choice Principle:

1. Installed in the irrelevant personnel not easy contact place; And easy to the power supply and decorate place;

2. Have cable feeder,it’s convenient opening fiber connection;

3. The installation location should avoid heat source and damp;

4. The installation location should be well ventilated.Need to vertical hang it on a wall or a mast, in order to ensure that the heat dissipation.When hanging, need to consider from the top≥ 50 cm and distance from the bottom ≥100 cm ;

Optical Fiber Connection

Optical fiber connectors should adopt type of FC/PC, in general it with black protection cover and corresponding to light adapter.Please with instruments cleaning detergents to spray when connecting. In order to avoid besmirch influence light way transmission, increase the light path insertion loss.Please follow the image when joining: plug the bolt aim at key slot (as per image),tighten up after plug: can not too tight or too loose. Otherwise, it will affect the loss of the optical connector.

P.S:The optical cable don’t crimp, need cover by good protection.